Objective: A growing body of research consistently shows that detained minors bear substantial mental health needs. However, the relation between mental disorder and criminal recidivism has largely remained unexplored. Our study examines whether psychiatric disorders increase the likelihood of recidivism after controlling for time at risk, criminal history, and the presence of other disorders. Method: Participants (n = 232) were detained male adolescents from all 3 youth detention centres in Flanders, Belgium, who were interviewed with the Diagnostic Interview Schedule for Children, Version IV. Two to 4 years later, information on serious recidivism was retrieved from the official judicial registration system. Serious recidivism was defined as having at least one arrest charge for violent, severe property crime, or substance-related offences. Results: Serious recidivism was high, with 81% (n = 191) of the participants being rearrested. Psychiatric disorders predicted neither serious recidivism in general nor violent and severe property recidivism. However, other drug use disorder (OR 2.41; 95% CI 1.22 to 4.75) and general comorbidity (OR 2.64; 95% CI 1.40 to 4.99) were significantly predictive of substance-related recidivism. Conclusion: Common psychiatric disorders in detained male adolescents do not significantly increase the likelihood of subsequent arrests, with the exception that substance use disorders appear to increase the risk of later substance-related recidivism. Effective treatment of these disorders may prevent detained juveniles to experience the detrimental outcomes associated with substance-related crimes as adults (for example, mental illness).